Mobile QR Code QR CODE : Journal of the Korean Society of Civil Engineers

  1. ๋ฐฐ์žฌ๋Œ€ํ•™๊ต ๊ฑด์„คํ™˜๊ฒฝ์ฒ ๋„๊ณตํ•™๊ณผ ๊ต์ˆ˜ (PaiChai University)
  2. ๋ฐฐ์žฌ๋Œ€ํ•™๊ต ๊ฑด์„คํ™˜๊ฒฝ์ฒ ๋„๊ณตํ•™๊ณผ ์„์‚ฌ๊ณผ์ • (PaiChai University)
  3. ๊ฒฝ๋‚จ๋Œ€ํ•™๊ต ํ† ๋ชฉ๊ณตํ•™๊ณผ ๊ต์ˆ˜ (Kyungnam University)


์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„, ์ง€์ง„๊ฐ•๋„ ๋ฒ”์œ„, ์ฒ ๊ทผ์ฝ˜ํฌ๋ฆฌํŠธ ๊ต๋Ÿ‰, ์†์ƒํ•œ๊ณ„์ƒํƒœ, ์ˆ˜ํ‰๋ณ€์œ„๋น„
Seismic fragility analysis, Earthquake intensity range, RC bridge, Damage limit state, Lateral drift ratio

  • 1. ์„œ ๋ก 

  • 2. ํ•ด์„๋Œ€์ƒ ๊ต๋Ÿ‰ ๋ฐ ๊ต๊ฐ์˜ ์†์ƒ ํ˜•ํƒœ

  •   2.1 ํ•ด์„๋Œ€์ƒ ๊ต๋Ÿ‰

  •   2.2 ๊ต๊ฐ์˜ ์†์ƒ ํ˜•ํƒœ

  • 3. ํ•ด์„๋Œ€์ƒ ๊ต๋Ÿ‰์˜ ํ•ด์„ ๋ชจ๋ธ ๋ฐ ๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅ์‘๋‹ต

  •   3.1 ํ•ด์„๋ชจ๋ธ

  •   3.2 ์ž…๋ ฅ์ง€์ง„ํŒŒ

  •   3.3 ๋Œ€์ƒ ๊ต๋Ÿ‰์˜ ๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅ์‘๋‹ต

  • 4. ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„

  •   4.1 ์ตœ์šฐ๋„๋ฒ•

  •   4.2 ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€์‘ํ•˜๋Š” ์ˆ˜ํ‰๋ณ€์œ„๋น„

  •   4.3 ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ 

  • 5. ๊ฒฐ ๋ก 

1. ์„œ ๋ก 

2016๋…„ 9์›” 12์ผ ๊ฒฝ๋ถ ๊ฒฝ์ฃผ์‹œ ๋‚จ์„œ์ชฝ ์•ฝ 11.6km์—์„œ ๊ทœ๋ชจ 5.8์˜ ์ง€์ง„์ด ๋ฐœ์ƒํ•˜์˜€๋‹ค. ๊ทœ๋ชจ 5.8์˜ ์ง€์ง„์€ ๊ตญ๋‚ด์—์„œ ์ง€์ง„๊ณ„์ธก์ด ์ด๋ฃจ์–ด์ง„ ์ดํ›„ ๊ฐ€์žฅ ํฐ ๊ทœ๋ชจ์˜ ์ง€์ง„์ด์—ˆ์ง€๋งŒ ๋‹คํ–‰์ด ์ธ๋ช…ํ”ผํ•ด๊ฐ€ ์—†์—ˆ๊ณ  ๊ตฌ์กฐ๋ฌผ์˜ ๋น„๊ตฌ์กฐ์ ์ธ ์š”์†Œ์— ๋ฐœ์ƒํ•œ ํ”ผํ•ด๋งŒ์ด ๋ณด๊ณ ๋˜์—ˆ๋‹ค(Lee et al., 2016; Lee and Jeon, 2016). ์ดํ›„ 1๋…„์ด ์กฐ๊ธˆ ์ง€๋‚œ 2017๋…„ 11์›” 15์ผ ํฌํ•ญ์‹œ ๋ถ๊ตฌ ๋ถ์ชฝ ์•ฝ 9km ์ง€์—ญ์—์„œ ๊ทœ๋ชจ 5.4์˜ ์ง€์ง„์ด ๋ฐœ์ƒํ•˜์˜€๊ณ  ํฌํ•ญ ๋ฐ ์ธ๊ทผ์ง€์—ญ์˜ ์ฃผ๊ฑฐ์šฉ ํ•„๋กœํ‹ฐ ๊ฑด๋ฌผ์— ์ƒ๋‹นํ•œ ํ”ผํ•ด๋ฅผ ์œ ๋ฐœํ•˜์˜€๋‹ค. 1๋…„์—ฌ์— ๊ฑธ์นœ ๋‘ ๋ฒˆ์˜ ์ง€์ง„์€ ์šฐ๋ฆฌ๋‚˜๋ผ์— ํฐ ๊ฒฝ๊ฐ์‹ฌ์„ ๋ถˆ๋Ÿฌ ์ผ์œผ์ผฐ๊ณ  ์šฐ๋ฆฌ๋‚˜๋ผ๋„ ๋” ์ด์ƒ ์ง€์ง„ ์•ˆ์ „์ง€๋Œ€๊ฐ€ ์•„๋‹ˆ๋ผ๋Š” ์šฐ๋ ค๊ฐ€ ์ปค์ง€๊ณ  ์žˆ๋‹ค. ์ด์™€ ๊ฐ™์€ ์‚ฌ์‹ค์€ ์ง€๋‚œ 10์—ฌ๋…„์— ๊ฑธ์ณ ์šฐ๋ฆฌ๋‚˜๋ผ๊ฐ€ ๊ทผ์ ‘ํ•ด ์žˆ๋Š” ํ™˜ํƒœํ‰์–‘ ์ง€์—ญ ๊ณณ๊ณณ์—์„œ ๋ฐœ์ƒํ•œ ๊ทœ๋ชจ 5.0 ์ด์ƒ์˜ ๊ฐ•์ง„์ด ๋’ท๋ฐ›์นจํ•ด์ค€๋‹ค. ๋Œ€ํ‘œ์ ์ธ ์˜ˆ๋กœ 2008๋…„ 5์›” 12์ผ ์ค‘๊ตญ ์“ฐ์ดจ์„ฑ์—์„œ ๋ฐœ์ƒํ•œ ๋ฆฌํžˆํ„ฐ ๊ทœ๋ชจ 7.9์˜ ๊ฐ•์ง„์— ์ด์–ด, 2011๋…„ 3์›” 11์ผ ์ผ๋ณธ ๋„ํ˜ธ์ฟ  ์ง€๋ฐฉ์—์„œ ๋ฐœ์ƒํ•œ ์ผ๋ณธ์˜ ์ง€์ง„ ๊ด€์ธก ์‚ฌ์ƒ ์ตœ๋Œ€์ธ ๋ฆฌํžˆํ„ฐ ๊ทœ๋ชจ 9.0์˜ ๋Œ€์ง€์ง„์œผ๋กœ ๋ง‰๋Œ€ํ•œ ํ”ผํ•ด๊ฐ€ ๋ฐœ์ƒํ•˜์˜€๋‹ค.

์ง€์ง„๊ณตํ•™์€ ๊ณผ๊ฑฐ์˜ ํฌ๊ณ  ์ž‘์€ ์ง€์ง„์— ์˜ํ•œ ๋‹ค์–‘ํ•œ ํ”ผํ•ด์‚ฌ๋ก€ ์กฐ์‚ฌ์™€ ์†์ƒ์›์ธ ๋ถ„์„ ๊ทธ๋ฆฌ๊ณ  ์ด์— ๋Œ€ํ•œ ๋ณด์ˆ˜/๋ณด๊ฐ•์— ๋Œ€ํ•œ ์‹คํ—˜์ , ํ•ด์„์  ์—ฐ๊ตฌ๋ฅผ ํ†ตํ•ด ๋ฐœ์ „ํ•˜์—ฌ ์™”๋‹ค. ์ง€์ง„ํ•˜์ค‘์— ์˜ํ•œ ๋‚ด์ง„์„ค๊ณ„ ๋˜ํ•œ ์ง€์ง„์— ์˜ํ•œ ํŒŒ๊ดด ์–‘์ƒ ๋ฐ ์†์ƒ์ˆ˜์ค€์— ๋Œ€ํ•œ ํ•ด์„ ๋ฐ ๋ชจ์‚ฌ์‹คํ—˜ ์—ฐ๊ตฌ๋ฅผ ํ†ตํ•ด ๊ณ ๋„์™€ ๋˜์–ด ์™”๋‹ค. ํ•˜์ง€๋งŒ ๊ทธ๋Ÿผ์—๋„ ๋ถˆ๊ตฌํ•˜๊ณ  ์œ„์— ์–ธ๊ธ‰๋œ ์ง€์ง„์žฌํ•ด๋Š” ์ง€์ง„ํ•˜์ค‘ ์ž์ฒด์˜ ๋ถˆํ™•์‹ค์„ฑ ๋•Œ๋ฌธ์— ๋ช…ํ™•ํ•˜๊ฒŒ ์˜ˆ์ธกํ•˜๊ธฐ๊ฐ€ ๋งค์šฐ ์–ด๋ ต๋‹ค. ์ตœ๊ทผ ๋“ค์–ด ์ง€์ง„ํ•˜์ค‘ ์ž์ฒด์˜ ๋ถˆํ™•์‹ค์„ฑ์„ ๊ณ ๋ คํ•˜๊ธฐ ์œ„ํ•ด ํ™•๋ฅ ๋ก ์  ๋‚ด์ง„์„ฑ๋Šฅํ‰๊ฐ€ ๋ฐฉ๋ฒ•์ธ ์ง€์ง„์œ„ํ—˜๋„ ํ•ด์„์ด๋‚˜ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์— ๊ด€ํ•œ ์—ฐ๊ตฌ๊ฐ€ ํ™œ๋ฐœํžˆ ์ˆ˜ํ–‰๋˜์–ด ์™”๋‹ค. ํŠนํžˆ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์€ ์ง€๋ฐ˜์šด๋™์˜ ํฌ๊ธฐ ์ง€์ˆ˜(์˜ˆ๋ฅผ ๋“ค์–ด, ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„, ์ตœ๋Œ€์ง€๋ฐ˜์†๋„, ์ตœ๋Œ€์ง€๋ฐ˜๋ณ€์œ„, ์ŠคํŽ™ํŠธ๋Ÿด ๊ฐ€์†๋„, ์ŠคํŽ™ํŠธ๋Ÿด ์†๋„, ์ŠคํŽ™ํŠธ๋Ÿด ๊ฐ•๋„ ๋“ฑ)์— ๋”ฐ๋ฅธ ์†์ƒ ๋ฐœ์ƒ์˜ ํ™•๋ฅ ์„ ๋‚˜ํƒ€๋‚ด๋Š” ๊ฒƒ์œผ๋กœ, 1980๋…„๋Œ€ ์ดˆ ์›์ž๋ ฅ๋ฐœ์ „์†Œ์˜ ํ™•๋ฅ ๋ก ์  ์ง€์ง„ ์•ˆ์ „์„ฑ ๋ถ„์„์„ ์œ„ํ•˜์—ฌ ๊ฐœ๋ฐœ๋˜์—ˆ๋‹ค. ์ตœ๊ทผ์—๋Š” ๋ฏธ๊ตญ, ์ผ๋ณธ ๋“ฑ์„ ์ค‘์‹ฌ์œผ๋กœ ์ผ๋ฐ˜ ํ† ๋ชฉ๊ตฌ์กฐ๋ฌผ์—๋„ ์ ์šฉํ•œ ์—ฐ๊ตฌ๊ฐ€ ํ™œ๋ฐœํžˆ ์ˆ˜ํ–‰๋˜์–ด ์™”์œผ๋ฉฐ, ๊ตญ๋‚ด์—์„œ๋„ ๊ต๋Ÿ‰๊ตฌ์กฐ๋ฌผ ๋ฐ ๊ฑด๋ฌผ ๋“ฑ์— ๋Œ€ํ•œ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์ด ํ™œ๋ฐœํžˆ ์ˆ˜ํ–‰๋˜์–ด ์™”๋‹ค.

Koh et al.(2003)์€ ์†Œ์„ฑ์†์ƒ๋ชจํ˜•์— ๊ธฐ์ดˆํ•œ ์†์ƒ์ง€์ˆ˜๋ฅผ ์ œ์•ˆํ•˜์˜€๊ณ , ์ด๋ฅผ ์ด์šฉํ•ด ์ง€์ง„ํ•˜์ค‘์— ๋Œ€ํ•œ ์†์ƒํ™•๋ฅ ์„ ๊ณ„์‚ฐํ•จ์œผ๋กœ์จ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„ ๋ฐ ์ง€์ง„์œ„ํ—˜๋„ ํ‰๊ฐ€๋ฅผ ์ˆ˜ํ–‰ํ•˜์˜€์œผ๋ฉฐ, Yi et al.(2004)์€ ๋ฉด์ง„๊ต๋Ÿ‰์— ๋Œ€ํ•ด ๊ต๊ฐ์˜ ํšŒ์ „์—ฐ์„ฑ๋„, ๊ต๋Ÿ‰๋ฐ›์นจ์˜ ๋ณ€์œ„, ์†์ƒ๋ชจํ˜• ๋“ฑ์˜ ๋‹ค์–‘ํ•œ ์†์ƒ์ง€์ˆ˜๋ฅผ ํ†ตํ•˜์—ฌ ์ง€์ง„์ทจ์•ฝ๋„ ๋ถ„์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๊ณ , ๋˜ํ•œ ์ง€์ง„์˜ ํ‰๊ท ์žฌํ˜„์ฃผ๊ธฐ๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ํ™•๋ฅ ๋ฐ€๋„ํ•จ์ˆ˜ ๋ณด๊ฐ„ ๊ธฐ๋ฒ•์„ ์ด์šฉํ•œ ์ง€์ง„์ทจ์•ฝ๋„ ๋ถ„์„ ๋“ฑ๋„ ์ œ์•ˆํ•˜์˜€๋‹ค. Kim et al.(2004)์€ ์„œ๋กœ ๋‹ค๋ฅธ ๋„ค ๊ฐ€์ง€ ๋ฐฉ๋ฒ•์˜ ์„ฑ๋Šฅ์ŠคํŽ™ํŠธ๋Ÿผ ๊ธฐ๋ฒ•์„ ํ†ตํ•ด ๊ตฌํ•ด์ง„ ์ทจ์•ฝ๋„ ๊ณก์„ ๋“ค์„ ๋น„์„ ํ˜• ์‹œ๊ฐ„์ด๋ ฅํ•ด์„ ๋ฐฉ๋ฒ•์— ์˜ํ•ด ๊ตฌํ•ด์ง„ ์ทจ์•ฝ๋„ ๊ณก์„ ๊ณผ ๋น„๊ต๋ถ„์„ํ•˜์˜€๊ณ , Kim et al.(2008)์€ ์ƒ์ดํ•œ ์ง€๋ฐ˜ํŠน์„ฑ์ด FCM ๊ต๋Ÿ‰์˜ ๋‚ด์ง„์„ฑ๋Šฅ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ์ง€์ง„์ทจ์•ฝ๋„ ๋ถ„์„๋ฐฉ๋ฒ•์œผ๋กœ ํ‰๊ฐ€ํ•˜์˜€๋‹ค. ํ•œํŽธ, ๊ตญ๋ฆฝ๋ฐฉ์žฌ์—ฐ๊ตฌ์†Œ์—์„œ๋Š” ๊ต๋Ÿ‰๊ตฌ์กฐ๋ฌผ์˜ ์ง€์ง„์ทจ์•ฝ๋„ํ•จ์ˆ˜ ๊ตญ์‚ฐํ™”์—ฐ๊ตฌ(National Institute for Disaster Prevention, 2007)๋ฅผ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ๋Š” ๋จผ์ € ๋ชจ๋“  ๊ตฌ์กฐํ˜•์‹ ๋“ฑ์— ๋”ฐ๋ฅธ ๊ต๋Ÿ‰์˜ ๋ถ„๋ฅ˜์ฒด๊ณ„๋ฅผ ์ œ์•ˆํ•˜์˜€๊ณ , ๊ฐ๊ฐ์˜ ๋ถ„๋ฅ˜๋œ ๊ต๋Ÿ‰ํ˜•์‹๋งˆ๋‹ค ์ˆ˜์น˜ํ•ด์„์„ ์œ„ํ•œ ๋Œ€ํ‘œ๊ต๋Ÿ‰๊ณผ ์ธ๊ณต์ง€์ง„์„ ์„ ์ •ํ•˜์—ฌ, ์ œ์•ˆ๋œ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„๋ฐฉ๋ฒ•์˜ ๊ตญ๋‚ด ๊ต๋Ÿ‰๊ตฌ์กฐ๋ฌผ์— ๋Œ€ํ•œ ์ ์šฉ์„ฑ์„ ํ‰๊ฐ€ํ•˜์˜€๋‹ค. ์ด์ฒ˜๋Ÿผ ๊ตญ๋‚ด์—์„œ๋„ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์— ๊ด€ํ•œ ์—ฐ๊ตฌ๊ฐ€ ํ™œ๋ฐœํ•˜๊ฒŒ ์ง„ํ–‰๋˜์–ด ์™”๋‹ค.

์ง€์ง„์ทจ์•ฝ๋„ ๋ถ„์„๋ฐฉ๋ฒ•์€ ์ผ๋ฐ˜์ ์œผ๋กœ ๊ณผ๊ฑฐ์˜ ์ง€์ง„ ํ”ผํ•ด์‚ฌ๋ก€ ๋ถ„์„์— ์˜ํ•œ ๊ฒฝํ—˜์ ์ธ ๋ฐฉ๋ฒ•๊ณผ ๋งŽ์€ ๊ณ„์ธก์ง€์ง„ํŒŒ๋ฅผ ์ด์šฉํ•˜์—ฌ ๊ตฌ์กฐ๋ฌผ์— ๋Œ€ํ•œ ๋น„์„ ํ˜• ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜๋Š” ํ•ด์„์  ๋ฐฉ๋ฒ•์ด ์žˆ๋‹ค. ๊ตญ๋‚ด์˜ ๊ฒฝ์šฐ์—๋Š” ์ง€์ง„ํ”ผํ•ด ๊ธฐ์ดˆ์ž๋ฃŒ ๋ฐ ๊ณ„์ธก์ง€์ง„ํŒŒ๊ฐ€ ๋ถ€์กฑํ•˜์—ฌ ํ•ด์„์  ์ง€์ง„์ทจ์•ฝ๋„ ๋ถ„์„์— ๋Œ€๋ถ€๋ถ„ ์˜์กดํ•˜๊ณ  ์žˆ๋‹ค. ํ•ด์„์  ์ง€์ง„์ทจ์•ฝ๋„ ๋ถ„์„ ๋ฐฉ๋ฒ•์€, ๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅํ•ด์„์— ์‚ฌ์šฉํ•˜๋Š” ์ž…๋ ฅ์ง€์ง„ํŒŒ๋กœ ์ธ๊ณต์ง€์ง„ํŒŒ์™€ ๊ธฐ์กด์˜ ์‹ค์ œ ๊ณ„์ธก์ง€์ง„ํŒŒ๋ฅผ ๋ฐฐ์œจ์กฐ์ • ํ•˜์—ฌ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•œ๋‹ค. ํ•˜์ง€๋งŒ ๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅํ•ด์„ ์‹œ, ์ž…๋ ฅ์ง€์ง„ํŒŒ์˜ ์ง€์ง„๊ฐ•๋„ ๋ฒ”์œ„์— ๋Œ€ํ•œ ๋ช…ํ™•ํ•œ ๊ทผ๊ฑฐ๊ฐ€ ์—†์–ด ๋งค์šฐ ํฐ ์ง€์ง„๊ฐ•๋„๊นŒ์ง€ ์ œํ•œ ์—†์ด ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜๋Š” ๊ฒฝ์šฐ๊ฐ€ ๋Œ€๋ถ€๋ถ„์œผ๋กœ ์ด๋Š” ์‹ค์ œ ๊ตฌ์กฐ๋ฌผ์—์„œ ๋ฐœ์ƒํ•˜๋Š” ๋ฌผ๋ฆฌ์  ์†์ƒ ๊ฑฐ๋™๊ณผ๋Š” ๋‹ค๋ฅธ ์†์ƒ์ดˆ๊ณผํ™•๋ฅ ์„ ๋‚˜ํƒ€๋‚ผ ์ˆ˜๋„ ์žˆ๋‹ค. ๋”ฐ๋ผ์„œ ์ด ์—ฐ๊ตฌ์—์„œ๋Š” ์ง€์ง„ํ•˜์ค‘์œผ๋กœ ์ธํ•ด ์‹ค์ œ ์†์ƒ์„ ์ž…์€ ์ฒ ๊ทผ์ฝ˜ํฌ๋ฆฌํŠธ ๊ต๋Ÿ‰์„ ์„ ํƒํ•˜์—ฌ ๋‹ค์–‘ํ•œ ์ง€์ง„๊ฐ•๋„ ๋ฒ”์œ„์— ๋Œ€ํ•œ ๋น„์„ ํ˜• ์‹œ๊ฐ„์ด๋ ฅํ•ด์„์„ ์ˆ˜ํ–‰ ํ›„, ํ•ด์„๊ฒฐ๊ณผ์— ์˜ํ•œ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์—ฌ ํ•ด์„๋Œ€์ƒ ๊ต๋Ÿ‰์˜ ์†์ƒํ˜•ํƒœ์— ๋”ฐ๋ฅธ ์†์ƒ์ดˆ๊ณผํ™•๋ฅ ์„ ํ•ฉ๋ฆฌ์ ์œผ๋กœ ๋ฐ˜์˜ํ•  ์ˆ˜ ์žˆ๋Š” ์ง€์ง„๊ฐ•๋„์˜ ๋ฒ”์œ„๋ฅผ ๊ฒ€ํ† ํ•˜์˜€๋‹ค.

2. ํ•ด์„๋Œ€์ƒ ๊ต๋Ÿ‰ ๋ฐ ๊ต๊ฐ์˜ ์†์ƒ ํ˜•ํƒœ

2.1 ํ•ด์„๋Œ€์ƒ ๊ต๋Ÿ‰

์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์—์„œ ์ง€์ง„๊ฐ•๋„์˜ ๋ฒ”์œ„๋ฅผ ๊ฒ€ํ† ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๊ณผ๊ฑฐ ์ง€์ง„์— ์˜ํ•ด ์†์ƒ์ด ๋ฐœ์ƒํ•œ ๊ต๋Ÿ‰์„ ์„ ์ •ํ•˜์˜€๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ ์„ ์ •ํ•œ ๊ต๋Ÿ‰์€ 1995๋…„ 1์›” 17์ผ์— ๋ฐœ์ƒํ•œ ์ผ๋ณธ ํšจ๊ณ ํ˜„ ๋‚œ๋ถ€์˜ ๊ณ ๋ฒ  ๋Œ€์ง€์ง„์—์„œ ์†์ƒ์„ ์ž…์€ ์ฒ ๊ทผ์ฝ˜ํฌ๋ฆฌํŠธ ๊ต๋Ÿ‰์œผ๋กœ ํ•œ์‹  ๊ณ ๊ฐ€๋„๋กœ ๊ต๋Ÿ‰ 3๋ฒˆ ๋ฃจํŠธ(route)์˜ ์ผ๋ถ€ ๊ตฌ๊ฐ„์ด๋‹ค(Elnashai et al., 1995). ํ•œ์‹  ๊ณ ๊ฐ€๋„๋กœ ๊ต๋Ÿ‰์€ 25~35m์˜ ๊ฒฝ๊ฐ„์ด ๋ฐ˜๋ณต์ ์œผ๋กœ ๊ตฌ์„ฑ๋˜์–ด ์žˆ์–ด ํ•ด์„์˜ ํŽธ์ด์„ฑ์„ ์œ„ํ•ด ๊ต๊ฐ์ด ์†์ƒ์ด ์ž…์€ ์ผ๋ถ€ ๊ตฌ๊ฐ„์„ ์ด ์—ฐ๊ตฌ์˜ ํ•ด์„๋Œ€์ƒ ๊ต๋Ÿ‰์œผ๋กœ ์„ ํƒํ•˜์˜€๋‹ค. ์„ ํƒ๋œ ๊ต๋Ÿ‰์˜ ๊ตฌ๊ฐ„์€ ์„ธ ๊ฐœ์˜ ๊ต๊ฐ P663, P664 ๋ฐ P665๋กœ ์ง€์ง€๋˜๋Š” ๊ตฌ๊ฐ„์œผ๋กœ ๋ฐ˜๋ณต์ ์ธ ๊ต๋Ÿ‰์˜ ํŠน์„ฑ์„ ๊ณ ๋ คํ•˜์—ฌ ๊ฒฝ๊ฐ„ S662์™€ S665์˜ ํ•œ์ชฝ ๋‹จ๋ถ€๋ฅผ ๊ต๋Œ€๋กœ ๊ฐ€์ •ํ•˜์˜€๋‹ค(Lee et al., 2005).

๊ต๋Ÿ‰์˜ ์ƒ๋ถ€๊ตฌ์กฐ๋Š” ํ•˜๋ถ€ ํ”Œ๋žœ์ง€์˜ ์ œ์›์ด ๋ณ€ํ™”ํ•˜๋Š” 6๊ฐœ์˜ Iํ˜• ๊ฐ• ์ฃผํ˜•์œผ๋กœ ๊ตฌ์„ฑ๋˜์–ด ์žˆ๊ณ  ๊ฐ• ์ฃผํ˜•์˜ ์ขŒ๊ตด ๋ฐฉ์ง€๋ฅผ ์œ„ํ•ด ์†์ด ๋นˆ ์›ํ˜•๊ฐ•๊ด€์ด ์ฃผํ˜• ์‚ฌ์ด์˜ ๋ธŒ๋ ˆ์ด์‹ฑ์œผ๋กœ ์‚ฌ์šฉ๋˜์—ˆ๋‹ค. ํ•˜๋ถ€๊ตฌ์กฐ์˜ ๊ฒฝ์šฐ ๋ชจ๋“  ๊ต๊ฐ ๋‹จ๋ฉด์€ ์ฒ ๊ทผ์ฝ˜ํฌ๋ฆฌํŠธ ์›ํ˜•๋‹จ๋ฉด์œผ๋กœ ์ด๋ฃจ์–ด์ ธ ์žˆ๊ณ , ๊ต๊ฐ P663์˜ ์ง€๋ฆ„์€ 2300mm์ธ ๋ฐ˜๋ฉด์— ๊ต๊ฐ P664์™€ P665์˜ ์ง€๋ฆ„์€ 2500mm์ด๋‹ค. ๋ชจ๋“  ๊ต๊ฐ ๋‹จ๋ฉด์˜ ์ถ•๋ฐฉํ–ฅ ์ฒ ๊ทผ์€ ๋‘ ๊ฒน์œผ๋กœ ๋ฐฐ๊ทผ๋˜์–ด ์žˆ์—ˆ์ง€๋งŒ, ๋ฐ”๊นฅ์ชฝ ์ฒ ๊ทผ์€ ๊ธฐ์ดˆ์˜ ๋ฐ‘๋ถ€๋ถ„์—์„œ ์ฝ”ํ•‘๋ถ€๊นŒ์ง€ ์—ฐ์†๋˜์–ด ์žˆ๋Š” ๋ฐ˜๋ฉด์— ์•ˆ์ชฝ ์ฒ ๊ทผ์€ ๊ธฐ์ดˆ์˜ ๋ฐ‘ ๋ถ€๋ถ„์œผ๋กœ๋ถ€ํ„ฐ 8770mm ๋†’์ด ๊นŒ์ง€๋งŒ ๋ฐฐ๊ทผ๋˜์—ˆ๋‹ค. ๊ต๊ฐ P663์€ ๊ธฐ์ดˆ์˜ ๋ฐ‘ ๋ถ€๋ถ„์—์„œ ์ฝ”ํ•‘๋ถ€ ์ƒ๋ถ€๊นŒ์ง€์˜ ์ด๊ธธ์ด๊ฐ€ 15539mm์ด๊ณ , ๊ต๊ฐ P664์™€ P665์˜ ์ด๊ธธ์ด๋Š” ๊ต๊ฐ P663 ๋ณด๋‹ค๋Š” ์•ฝ๊ฐ„ ์ž‘์€ 15234mm๋กœ ๋™์ผํ•˜๋‹ค. ๊ต๊ฐ์˜ ์ œ์› ๋ฐ ๋‹จ๋ฉด์ƒ์„ธ๋Š” ๊ฐ๊ฐ Figs. 1 and 2์— ๋‚˜ํƒ€๋‚˜ ์žˆ๋‹ค.

Figure_KSCE_38_5_02_F1.jpg
Fig. 1.

Dimensions of Piers

Figure_KSCE_38_5_02_F2.jpg
Fig. 2.

Cross-Section Details of Piers P664 and P665 (Values in Parentheses Represent Dimensions for Pier P663)

2.2 ๊ต๊ฐ์˜ ์†์ƒ ํ˜•ํƒœ

์„ ํƒ๋œ ๊ต๋Ÿ‰์˜ ์ƒ๋ถ€๊ตฌ์กฐ์—๋Š” ์†์ƒ์ด ๋ฐœ์ƒํ•˜์ง€ ์•Š์€ ๋ฐ˜๋ฉด์—, ๊ต๊ฐ์˜ ๊ฒฝ์šฐ ๊ต๊ฐ์˜ ์ค‘์•™๋†’์ด ๋ถ€๋ถ„์—์„œ ์‹ฌํ•œ ์†์ƒ์ด ๋ฐœ์ƒํ•˜์˜€๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ ๊ณ ๋ คํ•˜๊ณ  ์žˆ๋Š” ์„ธ ๊ต๊ฐ์— ๋ฐœ์ƒํ•œ ์ผ๋ฐ˜์ ์ธ ์†์ƒํ˜•ํƒœ๋กœ๋Š”, ๊ต๊ฐ์˜ ์ค‘์•™๋†’์ด ๋ถ€๋ถ„์—์„œ ์ฝ˜ํฌ๋ฆฌํŠธ ํ”ผ๋ณต๋ฐ•๋ฆฌ๊ฐ€ ์ค‘์•™๋ถ€์œ„ ๋‘˜๋ ˆ ์ „์ฒด์— ๊ฑธ์ณ ๋ฐœ์ƒํ•˜์˜€๊ณ , ์ถ•๋ฐฉํ–ฅ ์ฒ ๊ทผ์˜ ์ขŒ๊ตด๊ณผ ํ•จ๊ป˜ ์›ํ˜•ํ›„ํ”„๋กœ ์ด๋ฃจ์–ด์ง„ ํšก๊ตฌ์† ์ฒ ๊ทผ ์ผ๋ถ€๊ฐ€ ํŒŒ๋‹จ๋˜์—ˆ์œผ๋ฉฐ ์ด์— ๋”ฐ๋ผ ์‹ฌ๋ถ€๊ตฌ์†์ฝ˜ํฌ๋ฆฌํŠธ ๋˜ํ•œ ํŒŒ๊ดด๋˜์—ˆ๋‹ค. ๊ต๊ฐ ์†์ƒ ํ˜•ํƒœ์˜ ๋Œ€ํ‘œ์ ์ธ ๊ฒฝ์šฐ๋กœ ๊ต๊ฐ P664์˜ ํŒŒ๊ดด ์–‘์ƒ์„ Fig. 3์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค.

Figure_KSCE_38_5_02_F3.jpg
Fig. 3.

Representative Observed Damage Pattern of Pier P664 (Elnashai et al., 1995)

3. ํ•ด์„๋Œ€์ƒ ๊ต๋Ÿ‰์˜ ํ•ด์„ ๋ชจ๋ธ ๋ฐ ๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅ์‘๋‹ต

3.1 ํ•ด์„๋ชจ๋ธ

2.1์— ๊ธฐ์ˆ ๋œ ํ•ด์„ ๋Œ€์ƒ ๊ต๋Ÿ‰์— ๋Œ€ํ•œ ๋น„์„ ํ˜• ํ•ด์„๋ชจ๋ธ์„ ๊ฐœ๋ฐœํ•˜์˜€๋‹ค. ๋Œ€์ƒ ๊ต๋Ÿ‰์˜ ๋น„์„ ํ˜• ํ•ด์„๋ชจ๋ธ์€ ํ™”์ด๋ฒ„(fiber) ์š”์†Œ๋ฅผ ์‚ฌ์šฉํ•œ ๋‹จ๋ฉดํ•ด์„ํ”„๋กœ๊ทธ๋žจ์ธ ZeusNL (Elnashai et al., 2001)์—์„œ ์ œ๊ณตํ•˜๋Š” ๋‹ค์–‘ํ•œ ๋น„์„ ํ˜• ์š”์†Œ ๋ชจ๋ธ์„ ์‚ฌ์šฉํ•˜์—ฌ ๊ฐœ๋ฐœํ•˜์˜€๋‹ค.

๊ต๊ฐ์˜ ๊ฒฝ์šฐ, ์ฒ ๊ทผ์ฝ˜ํฌ๋ฆฌํŠธ ์›ํ˜• ๋‹จ๋ฉด์„ ์‚ฌ์šฉํ•˜์˜€๊ณ  ๋‹จ๋ฉด๋‚ด์˜ ์ •๋ฐ€ํ•œ ํ™”์ด๋ฒ„ ๋‹จ๋ฉดํ•ด์„์„ ์œ„ํ•ด 200๊ฐœ์˜ ๋ชจ๋‹ˆํ„ฐ๋ง ์š”์†Œ๋กœ ๋ถ„ํ• ํ•˜์˜€๋‹ค. ์›ํ˜• ๋‹จ๋ฉด ๋‚ด ์žฌ๋ฃŒ๋ชจ๋ธ์€ ์ถ•๋ฐฉํ–ฅ ์ฒ ๊ทผ, ๋น„๊ตฌ์† ๋ฐ ๊ตฌ์†์ฝ˜ํฌ๋ฆฌํŠธ๋กœ ์žฌ๋ฃŒ๋ฅผ ๊ตฌ๋ถ„ํ•˜์—ฌ ์ ์šฉํ•˜์˜€๋‹ค. ์ถ•๋ฐฉํ–ฅ ์ฒ ๊ทผ์˜ ์žฌ๋ฃŒ ๋ชจ๋ธ์€ ์ด์„ ํ˜• ์‘๋ ฅ-๋ณ€ํ˜•๋ฅ  ๊ด€๊ณ„์‹์„ ์ด์šฉํ•˜์˜€๊ณ , ๋น„๊ตฌ์† ๋ฐ ๊ตฌ์†์ฝ˜ํฌ๋ฆฌํŠธ ์žฌ๋ฃŒ๋ชจ๋ธ์€ Mander et al.(1988) ๋ชจ๋ธ์„ ๊ธฐ๋ณธ์œผ๋กœ Martinez-Rueda and Elnashai(1997)์— ์˜ํ•ด ์ˆ˜์ •๋œ ์‘๋ ฅ-๋ณ€ํ˜•๋ฅ  ๊ด€๊ณ„์‹์„ ์ด์šฉํ•˜์˜€๋‹ค. ๊ตฌ์†์ฝ˜ํฌ๋ฆฌํŠธ ์žฌ๋ฃŒ๋ชจ๋ธ์— ํ•„์š”ํ•œ ๊ตฌ์†๊ณ„์ˆ˜๋Š” Mander et al.(1988)์˜ ์ œ์•ˆ์‹์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ๊ต๊ฐ์˜ ๋น„ํƒ„์„ฑ ์š”์†Œ ๊ตฌ์„ฑ์— ์žˆ์–ด ์บ”ํ‹ธ๋ ˆ๋ฒ„ ๊ต๊ฐ์˜ ์œ„ํ—˜๋‹จ๋ฉด์ธ ๋ฐ‘๋ถ€๋ถ„์—๋Š” ๋น„๊ต์  ์งง์€ ๋น„ํƒ„์„ฑ ์š”์†Œ๋ฅผ ์‚ฌ์šฉํ•œ ๋ฐ˜๋ฉด ์ฝ”ํ•‘๋ถ€๋กœ ๊ฐˆ์ˆ˜๋ก ๋น„๊ต์  ๊ธด ๋น„ํƒ„์„ฑ ์š”์†Œ๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ๊ต๊ฐ์˜ ์œ„ํ—˜๋‹จ๋ฉด์—์„œ ์†Œ์„ฑํžŒ์ง€ ๊ตฌ๊ฐ„์ด ๋น„๊ต์  ์ •ํ™•ํ•˜๊ฒŒ ๋ชจ์‚ฌ๋˜๋„๋ก ๋ชจ๋ธ๋ง์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค.

์ƒ๋ถ€๊ตฌ์กฐ์˜ ๊ฒฝ์šฐ, ์—ฌ์„ฏ ๊ฐœ์˜ ์ฃผํ˜•๊ณผ ์ฝ˜ํฌ๋ฆฌํŠธ ์Šฌ๋ž˜๋ธŒ์— ๋Œ€ํ•ด ๋“ฑ๊ฐ€์˜ ํœจ ๊ฐ•์„ฑ๊ณผ ๋น„ํ‹€๋ฆผ ๊ฐ•์„ฑ์„ ๊ฐ–๋Š” ๋“ฑ๊ฐ€์˜ ๋‹จ์ผ Iํ˜• ๋‹จ๋ฉด์œผ๋กœ ํ•ด์„๋ชจ๋ธ์„ ๊ตฌ์„ฑํ•˜์˜€๋‹ค. ๋“ฑ๊ฐ€์˜ ๋‹จ์ผ Iํ˜• ๋‹จ๋ฉด ๊ณ„์‚ฐ์€ ์ผ๋ณธ์˜ ๋„๋กœ๊ต ๋‚ด์ง„์„ค๊ณ„๊ธฐ์ค€(Specifications for Highway Bridges Part V : Seismic Design, 1990)์—์„œ ์ œ์•ˆ๋œ ๋ฐฉ๋ฒ•์„ ์ ์šฉํ•˜์˜€๋‹ค. ๊ณ ์ •ํ•˜์ค‘ ๊ณ„์‚ฐ์—์„œ ์ƒ๋ถ€๊ตฌ์กฐ์™€ ๊ต๊ฐ์˜ ๋‹จ๋ฉด ๋ฐ ๋„๋กœํฌ์žฅ๊ณผ ์ฝ˜ํฌ๋ฆฌํŠธ ์Šฌ๋ž˜๋ธŒ์˜ ๋‘๊ป˜ 170mm๋ฅผ ํฌํ•จ์‹œํ‚จ ๋ฐ˜๋ฉด์—, ํ™œํ•˜์ค‘์€ ๊ณ ๋ คํ•˜์ง€ ์•Š์•˜๋‹ค. ๊ต๋Ÿ‰๋ฐ›์นจ ๊ณ ์ •๋‹จ ๋ฒ ์–ด๋ง์˜ ๊ฒฝ์šฐ ๊ต์ถ•์ง๊ฐ๋ฐฉํ–ฅ๊ณผ ๊ต๊ฐ์ถ•๋ฐฉํ–ฅ์— ๋Œ€ํ•œ ํšŒ์ „ ์ž์œ ๋„๋ฅผ ํ—ˆ์šฉํ•œ ๋ฐ˜๋ฉด์— ๊ทธ ์™ธ ๋ชจ๋“  ์ถ•์— ๋Œ€ํ•œ ๋ณ€์œ„ ๋ฐ ํšŒ์ „ ์ž์œ ๋„๋ฅผ ๊ตฌ์†ํ•˜์˜€๊ณ , ๊ฐ€๋™๋‹จ ๋ฒ ์–ด๋ง์—์„œ๋Š” ๊ณ ์ •๋‹จ ๋ฒ ์–ด๋ง์˜ ๊ตฌ์†์กฐ๊ฑด์—์„œ ๊ต์ถ•๋ฐฉํ–ฅ์— ๋Œ€ํ•œ ๋ณ€์œ„ ์ž์œ ๋„๋ฅผ ์ถ”๊ฐ€์ ์œผ๋กœ ํ—ˆ์šฉํ•˜์˜€๋‹ค. ํ•ด์„ ๋Œ€์ƒ ๊ต๋Ÿ‰์— ๋Œ€ํ•œ ํ•ด์„๋ชจ๋ธ์€ Fig. 4์— ๋‚˜ํƒ€๋‚˜ ์žˆ๋‹ค.

Figure_KSCE_38_5_02_F4.jpg
Fig. 4.

Analytical Model of the Bridge Under Consideration

3.2 ์ž…๋ ฅ์ง€์ง„ํŒŒ

๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅํ•ด์„์€ ํŠน์ • ์ž…๋ ฅ์ง€์ง„์— ๋Œ€ํ•œ ๊ตฌ์กฐ๋ฌผ์˜ ์‘๋‹ต์„ ๊ตฌํ•˜๋Š” ๊ฒƒ์œผ๋กœ์„œ, ์ง€์ง„์˜ ํฌ๊ธฐ, ์ง€์†์‹œ๊ฐ„, ์ฃผํŒŒ์ˆ˜ ํŠน์„ฑ ๋“ฑ์— ๋”ฐ๋ฅธ ์ž…๋ ฅ์ง€์ง„ํŒŒ์˜ ๋ถˆํ™•์‹ค์„ฑ์„ ํฌํ•จํ•˜๊ณ  ์žˆ๋‹ค. ๋”ฐ๋ผ์„œ ๊ตฌ์กฐ๋ฌผ์˜ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์„ ์œ„ํ•ด์„œ๋Š” ์ถฉ๋ถ„ํ•œ ์ˆ˜์˜ ์ž…๋ ฅ์ง€์ง„ํŒŒ๋ฅผ ์‚ฌ์šฉํ•  ํ•„์š”๊ฐ€ ์žˆ๋‹ค. ๋ฏธ๊ตญ๊ณผ ์ผ๋ณธ์˜ ๊ฒฝ์šฐ์—๋Š” ๊ณผ๊ฑฐ ๋ฐœ์ƒํ•œ ์ง€์ง„์— ๋Œ€ํ•œ ๋งŽ์€ ์ง€์ง„๊ณ„์ธก ์ž๋ฃŒ๊ฐ€ ์ •๋ฆฌ๋˜์–ด ์žˆ๋Š” ๋ฐ˜๋ฉด์—, ์šฐ๋ฆฌ๋‚˜๋ผ์˜ ๊ฒฝ์šฐ์—๋Š” ์ง€์ง„ํŒŒ์˜ ๊ณ„์ธก์ž๋ฃŒ๊ฐ€ ๋ถ€์กฑํ•œ ์‹ค์ •์ด๋‹ค. ์ด์— ์ด ์—ฐ๊ตฌ์—์„œ๋Š” ๊ตญ์™ธ์—์„œ ๊ณ„์ธก๋œ 25๊ฐœ์˜ ์ง€์ง„ํŒŒ๋ฅผ ์„ ํƒํ•˜์˜€๋‹ค. ์ด ๊ณ„์ธก์ง€์ง„ํŒŒ์˜ ์„ ํƒ์€ ์ฃผ๊ด€์ ์ด์ง€๋งŒ ๊ฐ€๋Šฅํ•œ ๋‹ค์–‘ํ•œ ์ฃผํŒŒ์ˆ˜ ํŠน์„ฑ ๋ฐ ์ŠคํŽ™ํŠธ๋Ÿด ๊ฐ€์†๋„ ๋ถ„ํฌ๋ฅผ ๊ฐ–๋„๋ก ํ•˜์˜€๋‹ค. ์„ ํƒํ•œ ๊ณ„์ธก์ง€์ง„ํŒŒ๋Š” Table 1์— ์ •๋ฆฌํ•˜์—ฌ ๋‚˜ํƒ€๋‚ด์—ˆ๊ณ , ๊ฐ ๊ณ„์ธก์ง€์ง„ํŒŒ์— ๋Œ€ํ•ด ์ž„๊ณ„๊ฐ์‡ ์˜ 5%์— ๋Œ€์‘ํ•˜๋Š” ์‘๋‹ต์ŠคํŽ™ํŠธ๋Ÿผ์„ Fig. 5์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. Fig. 5์—์„œ ์•Œ ์ˆ˜ ์žˆ๋Š” ๋ฐ”์™€ ๊ฐ™์ด, ์ด ์—ฐ๊ตฌ์—์„œ ์„ ํƒํ•œ 25๊ฐœ์˜ ์ง€์ง„ํŒŒ๋“ค์€ ์ตœ๋Œ€ ์ฆํญ์—์„œ์˜ ์ตœ๋Œ€ ์ŠคํŽ™ํŠธ๋Ÿด ๊ฐ€์†๋„ ๋ฐ ๋Œ€์‘ ์ฃผ๊ธฐ๊ฐ€ ๋น„๊ต์  ๊ณ ๋ฅด๊ฒŒ ๋ถ„ํฌ๋˜์–ด ์žˆ์–ด ์„ ํƒ์˜ ํƒ€๋‹น์„ฑ์„ ๋’ท๋ฐ›์นจํ•˜๊ณ  ์žˆ๋‹ค.

Table 1. Selected Input Ground Motions

Earthquakes Year Station ML Soil Transverse component
PGA (g) A/V (g/m/s)
Chalfant Valley, USA 1986 Zack Brothers Ranch 6.3 deep broad 0.447 1.211
Coalinga, USA 1983 Pleasant Valley 6.7 deep broad 0.592 0.983
Coalinga, USA 1983 Oil City 6.0 stiff 0.866 2.052
Coalinga, USA 1983 Pleasant Valley 6.0 deep broad 0.602 1.730
Coalinga, USA 1983 CHP(temp) 5.3 deep broad 0.733 1.949
Gazli, Uzbekistan 1976 Gazli 6.4 very soft 0.720 1.148
Imperial Valley, USA 1979 Bons Corner 6.6 deep broad 0.775 1.688
Imperial Valley, USA 1979 El Centro Array#4 6.6 deep broad 0.485 1.297
Imperial Valley, USA 1979 El Centro Array#5 6.6 deep broad 0.519 1.107
Ionian, Greece 1973 Lefkada-OTE Building 5.3 soft 0.525 0.921
Kobe, Japan 1995 Takarazuka 6.9 soft deep 0.694 0.814
Loma Prieta, USA 1989 Capitola 6.9 deep narrow 0.529 1.449
Loma Prieta, USA 1989 Corralitos 6.9 stiff 0.644 1.167
Loma Prieta, USA 1989 Coyote Lake dam 6.9 rock 0.484 1.219
Loma Prieta, USA 1989 Gilroy Array#4 6.9 deep broad 0.417 1.075
Mammoth Lakes, USA 1980 Long Valley dam 6.2 rock 0.921 3.187
Morgan Hill, USA 1984 Coyote Lake Dam 6.2 rock 1.298 1.606
Morgan Hill, USA 1984 Halls Valley 6.2 deep narrow 0.312 0.792
N. Palm Springs, USA 1986 North Palm Springs 5.9 deep broad 0.694 2.053
N. Palm Springs, USA 1986 Whitewater Trout Farm 5.9 deep narrow 0.612 1.943
Northridge, USA 1994 Newhall 6.6 deep broad 0.590 0.607
Northridge, USA 1994 Santa Monica City Hall 6.6 deep broad 0.883 2.118
Northridge, USA 1994 Sylmar-Olive View Med FF 6.6 deep broad 0.843 0.650
San Fernando, USA 1971 Pacoima Dam 6.6 stiff 1.226 1.090
Tabas, Iran 1978 Tabas 7.7 deep narrow 0.852 0.702

Figure_KSCE_38_5_02_F5.jpg
Fig. 5.

Response Spectrum of the Selected Input Ground Motions

3.3 ๋Œ€์ƒ ๊ต๋Ÿ‰์˜ ๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅ์‘๋‹ต

3.1์—์„œ ์ •์˜๋œ ํ•ด์„๋ชจ๋ธ์— ์„ ํƒ๋œ 25๊ฐœ์˜ ๊ณ„์ธก์ง€์ง„ํŒŒ๋ฅผ ์ ์šฉํ•˜์—ฌ ๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅํ•ด์„์—์„œ๋Š” ๊ณ„์ธก์ง€์ง„ํŒŒ์— ๋Œ€ํ•ด 0.1g์—์„œ 2.0g๊นŒ์ง€ 0.1g์˜ ๊ฐ„๊ฒฉ์œผ๋กœ ๋ฐฐ์œจ์กฐ์ •์„ ํ•˜์—ฌ ๊ต๊ฐ์˜ ๋น„์„ ํ˜• ์‘๋‹ต์„ ๊ฒ€ํ† ํ•˜์˜€๋‹ค. ๊ต๊ฐ์˜ ๋น„์„ ํ˜• ์‘๋‹ต ๋ณ€์ˆ˜๋กœ, ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์—์„œ ์‚ฌ์šฉํ•˜๋Š” ์†์ƒํ•œ๊ณ„์ƒํƒœ์™€์˜ ๋ถ€ํ•ฉ์„ฑ์„ ์œ„ํ•ด ๊ต๊ฐ์˜ ์ˆ˜ํ‰๋ณ€์œ„๋น„๋ฅผ ์„ ํƒํ•˜์˜€๋‹ค. Fig. 3์— ๊ต๊ฐ P664์˜ ์†์ƒ์ƒํƒœ๋ฅผ ๋Œ€ํ‘œ์ ์œผ๋กœ ๋‚˜ํƒ€๋‚ด์—ˆ์œผ๋ฏ€๋กœ ๊ต๊ฐ P664์˜ ์ตœ๋Œ€ ์ˆ˜ํ‰๋ณ€์œ„๋น„๋ฅผ ์„ธ ๋‹จ๊ณ„์˜ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„ ๋ฒ”์œ„๋ณ„๋กœ Fig. 6์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. Fig. 6์—์„œ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋Š” ๋ฐ”์™€ ๊ฐ™์ด, ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„ ์ฆ๊ฐ€์— ๋น„๋ก€์ ์œผ๋กœ ์ตœ๋Œ€ ์ˆ˜ํ‰๋ณ€์œ„๋น„๊ฐ€ ์ฆ๊ฐ€ํ•จ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ํ•˜์ง€๋งŒ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„ ๋ฒ”์œ„๊ฐ€ ์ปค์ง์— ๋”ฐ๋ผ ์ฆ๊ฐ€ ๋น„์œจ์ด ๋‹ค์†Œ ๊ฐ์†Œํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋‚˜ํƒ€๋‚ด์—ˆ๊ณ  ์ด๋Š” ๋ชจ๋“  ๊ต๊ฐ์—์„œ ๋™์ผํ•˜์˜€๋‹ค.

Figure_KSCE_38_5_02_F6.jpg
Fig. 6.

Maximum Drift Ratio Distribution of Pier P664

4. ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„

3.3์—์„œ ๊ตฌํ•ด์ง„ ๊ต๊ฐ์˜ ์ตœ๋Œ€ ์ˆ˜ํ‰๋ณ€์œ„๋น„ ์‘๋‹ต์„ ์ด์šฉํ•˜์—ฌ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ์ง€์ง„์ทจ์•ฝ๋„๋Š” ์ผ๋ฐ˜์ ์œผ๋กœ ๊ตฌ์กฐ๋ฌผ์— ํŠน์ •ํ•œ ์ง€์ง„ํ•˜์ค‘์ด ์ž‘์šฉํ•  ๋•Œ, ๊ตฌ์กฐ๋ฌผ์˜ ์‘๋‹ต์ด ์†์ƒํ•œ๊ณ„์ƒํƒœ๋ฅผ ์ดˆ๊ณผํ•  ๋•Œ์˜ ํ™•๋ฅ ๋กœ ๊ฒฐ์ •๋œ๋‹ค. ์ง€์ง„์ทจ์•ฝ๋„ ํ•จ์ˆ˜์˜ ๊ตฌ์กฐ์‘๋‹ต ํ™•๋ฅ ๋ชจ๋ธ์„ ๊ฒฐ์ •ํ•˜๋Š” ๋ฐฉ๋ฒ•์œผ๋กœ๋Š”, ๊ณ„์ธก์ง€์ง„ํŒŒ๋ฅผ ๋ฐฐ์œจ์กฐ์ • ์—†์ด ์‚ฌ์šฉํ•˜๋Š” ํด๋ผ์šฐ๋“œ(cloud) ๋ฐฉ๋ฒ•, ๊ณ„์ธก์ง€์ง„ํŒŒ๋ฅผ ๋ฐฐ์œจ์กฐ์ •ํ•˜์—ฌ ์‚ฌ์šฉํ•˜๋Š” ์ŠคํŠธ๋ผ์ž…(stripe) ๋ฐฉ๋ฒ•์œผ๋กœ ๋‚˜๋ˆ„์–ด์ง„๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” 25๊ฐœ์˜ ๋น„๊ต์  ์ ์€ ์ˆ˜์˜ ๊ณ„์ธก์ง€์ง„ํŒŒ๋ฅผ ์‚ฌ์šฉํ•˜์˜€๊ธฐ ๋•Œ๋ฌธ์— ๊ณ„์ธก์ง€์ง„ํŒŒ์— ๋Œ€ํ•ด ๋ฐฐ์œจ์กฐ์ •์„ ํ•˜์—ฌ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๊ณ , ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์„ ์œ„ํ•ด ๊ตญ๋‚ด์™ธ์—์„œ ๋นˆ๋ฒˆํ•˜๊ฒŒ ์‚ฌ์šฉ๋˜๊ณ  ์žˆ๋Š” Shinozuka et al.(2000)์ด ์ œ์•ˆํ•œ ๋ฐฉ๋ฒ•์„ ์„ ํƒํ•˜์˜€๋‹ค.

4.1 ์ตœ์šฐ๋„๋ฒ•

Shinozuka et al.(2000)์€ ์ง€์ง„์ทจ์•ฝ๋„ ํ•จ์ˆ˜๋ฅผ ๋Œ€์ˆ˜์ •๊ทœ๋ถ„ํฌํ•จ์ˆ˜(log-normal distribution function)๋กœ ํ‘œํ˜„ํ•˜๊ณ , ๋Œ€์ˆ˜์ •๊ทœ๋ถ„ํฌํ•จ์ˆ˜์˜ ์ค‘์•™๊ฐ’(median value)๊ณผ ๋Œ€์ˆ˜ํ‘œ์ค€ํŽธ์ฐจ(log-standard deviation)๋ฅผ ์ตœ์šฐ๋„์ถ”์ •๋ฒ•(Maximum Likelihood Estimation)์— ์˜ํ•˜์—ฌ ์ถ”์ •ํ•˜๋Š” ๊ฒƒ์„ ์ œ์•ˆํ•˜์˜€๋‹ค. Shinozuka et al.(2000)์€ ์‹ค์ œ ์ง€์ง„์— ์˜ํ•ด ์†์ƒ๋œ ๊ตฌ์กฐ๋ฌผ์˜ ํ”ผํ•ด์ž๋ฃŒ๋ฅผ ๊ทผ๊ฑฐ๋กœ ๊ฒฝํ—˜์  ์ง€์ง„์ทจ์•ฝ๋„ ํ‰๊ฐ€๋ฅผ ์ˆ˜ํ–‰ํ•˜์—ฌ ๋Œ€์ˆ˜์ •๊ทœ๋ถ„ํฌํ•จ์ˆ˜๋กœ ์ •์˜๋œ ์ทจ์•ฝ๋„ ๊ณก์„ ์˜ ํƒ€๋‹น์„ฑ์„ ์ž…์ฆํ•˜์˜€๋‹ค. ์ตœ์šฐ๋„์ถ”์ •๋ฒ•์€ ์ตœ์šฐ๋„ ํ•จ์ˆ˜๋ฅผ ์ •์˜ํ•˜๋Š” ๋ฐฉ๋ฒ•์— ๋”ฐ๋ผ ์„ธ ๊ฐ€์ง€๋กœ ๊ตฌ๋ถ„ํ•  ์ˆ˜ ์žˆ์ง€๋งŒ, ์ด ์—ฐ๊ตฌ์—์„œ๋Š” ๊ฐ๊ธฐ ๋‹ค๋ฅธ ์†์ƒ์ƒํƒœ์— ๋Œ€ํ•œ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์ด ์„œ๋กœ ๊ต์ฐจํ•˜๋Š” ๊ฒฝ์šฐ๊ฐ€ ๋ฐœ์ƒํ•  ์ˆ˜ ์žˆ๋Š” ํ˜„์ƒ์„ ๋ฐฉ์ง€ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๊ฐ ์†์ƒ๋‹จ๊ณ„๋ณ„๋กœ ์ค‘์•™๊ฐ’์€ ์ตœ์šฐ๋„ ํ•จ์ˆ˜๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ์ถ”์ •ํ•˜๋˜ ๋Œ€์ˆ˜ํ‘œ์ค€ํŽธ์ฐจ๋Š” ๋Œ€์ƒ ๊ต๋Ÿ‰์˜ ๋ชจ๋“  ์†์ƒ๋‹จ๊ณ„๋ณ„ ์ž๋ฃŒ๋ฅผ ์ด์šฉํ•˜๋Š” ๊ณตํ†ต๋Œ€์ˆ˜ํ‘œ์ค€ํŽธ์ฐจ(common log-standard deviation)๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์„ ์œ ๋„ํ•˜์˜€๋‹ค.

์ž„์˜์˜ ์ง€์ง„์— ์˜ํ•œ ๊ตฌ์กฐ๋ฌผ์˜ ์†์ƒ๋‹จ๊ณ„๋ฅผ Nstate๊นŒ์ง€ ๊ณ ๋ คํ•˜๋Š” ๊ฒฝ์šฐ, ์†์ƒ๋‹จ๊ณ„ ๊ฐœ์ˆ˜๋งŒํผ์˜ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์„ ์–ป์„ ์ˆ˜ ์žˆ์œผ๋ฉฐ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„๊ฐ€ ai์ธ ์ž„์˜์˜ ์ง€์ง„์— ๋Œ€ํ•˜์—ฌ ๊ตฌ์กฐ๋ฌผ์ด ๋ฏธ๋ฆฌ ์ •์˜๋œ ๊ฐ ์„ฑ๋Šฅํ•œ๊ณ„ Ek๋ฅผ ์ดˆ๊ณผํ•  ํ™•๋ฅ , ์ฆ‰ ์ง€์ง„์†์ƒ ๊ฐ€๋Šฅ์„ฑ์„ Eq. (1)๊ณผ ๊ฐ™์ด Fj(ai, cj, ๐œ)๋กœ ๋‚˜ํƒ€๋‚ด๊ณ , ๋‹ค์Œ๊ณผ ๊ฐ™์ด ์ •์˜ํ•  ์ˆ˜ ์žˆ๋‹ค.

์ˆ˜์‹  (1)

์—ฌ๊ธฐ์„œ, cj์™€ ๐œ๋Š” ์†์ƒ์ง€์ˆ˜ j์— ๋Œ€ํ•œ ๋Œ€์ˆ˜์ •๊ทœ๋ถ„ํฌํ•จ์ˆ˜์˜ ์ค‘์•™๊ฐ’๊ณผ ๊ณตํ†ต๋Œ€์ˆ˜ํ‘œ์ค€ํŽธ์ฐจ์ด๋ฉฐ, ์†์ƒ์ƒํƒœ๋Š” j=1, 2, โ€ฆ, Nstate๋กœ ๋‚˜ํƒ€๋‚ธ๋‹ค. ์ง€์ง„๋ฐœ์ƒ ํ›„ ๊ต๋Ÿ‰์˜ ์ƒํƒœ๋ฅผ Ek๋กœ ์ •์˜ํ•˜๋ฉด, ๊ต๋Ÿ‰์˜ ์†์ƒ์ด Ek์™€ Ek+1 ์‚ฌ์ด์— ์žˆ์„ ํ™•๋ฅ  Pik=P(ai, Ek)์€ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์„ ์ด์šฉํ•˜์—ฌ ๊ตฌํ•  ์ˆ˜ ์žˆ๋‹ค. ๋งŒ์•ฝ, ์†์ƒ๋‹จ๊ณ„๋ฅผ ๊ฒฝ๋ฏธ, ๋ณดํ†ต, ์‹ฌ๊ฐ์˜ ์„ธ ๋‹จ๊ณ„๋กœ ๊ตฌ๋ถ„ํ•˜๋Š” ๊ฒฝ์šฐ, ๊ฐ ์†์ƒ๋‹จ๊ณ„์— ๋Œ€์‘ํ•˜๋Š” ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์„ ๊ฐ๊ฐ F1(โ€ค), F2(โ€ค), F3(โ€ค)๋ผ๊ณ  ํ•˜๊ณ  ์ง€์ง„๋ฐœ์ƒ ํ›„ ๊ต๋Ÿ‰์˜ ์†์ƒ์ƒํƒœ๋ฅผ ๋ฌด์†์ƒ, ๊ฒฝ๋ฏธ, ๋ณดํ†ต ๊ทธ๋ฆฌ๊ณ  ์‹ฌ๊ฐ์œผ๋กœ ๊ตฌ๋ถ„ํ•˜์—ฌ ๊ฐ ์†์ƒ์ƒํƒœ๋ฅผ E1, E2, E3 ๊ทธ๋ฆฌ๊ณ  E4๋กœ ์ •์˜ํ•˜๋ฉด j๋ฒˆ์งธ ์†์ƒ์ƒํƒœ์— ๋Œ€ํ•œ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์€ ์•„๋ž˜ Eq. (2)์™€ ๊ฐ™์ด ์ •์˜ํ•  ์ˆ˜ ์žˆ๋‹ค.

์ˆ˜์‹  (2)

์ตœ์šฐ๋„ ํ•จ์ˆ˜๋Š” ๋‹ค์Œ Eq. (3)๊ณผ ๊ฐ™์ด ๊ต๋Ÿ‰์ด ์ง€์ง„ ๋ฐœ์ƒ ํ›„ ์–ด๋–ค ์ƒํƒœ์— ์žˆ๋Š” ์ง€๋ฅผ ํŒ๋‹จํ•œ ํ›„, ํ•ด๋‹น๋˜๋Š” ํ™•๋ฅ ๋งŒ์„ ์ฆ๊ฐ€์‹œํ‚ฌ ์ˆ˜ ์žˆ๋„๋ก ๊ตฌ์„ฑํ•œ๋‹ค.

์ˆ˜์‹  (3)

์—ฌ๊ธฐ์„œ, xik๋Š” ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„ PGA(g)=ai์ธ ์ง€์ง„์— ๋Œ€ํ•˜์—ฌ, ๊ต๋Ÿ‰์ด Ek์˜ ์†์ƒ์ƒํƒœ๊ฐ€ ๋ฐœ์ƒํ•  ๊ฒฝ์šฐ์—๋Š” xik์ด๊ณ  ๊ทธ๋ ‡์ง€ ์•Š์„ ๊ฒฝ์šฐ์—๋Š” xik์˜ ๊ฐ’์„ ๊ฐ€์ง„๋‹ค. ์œ„์™€ ๊ฐ™์€ ์ตœ์šฐ๋„ ํ•จ์ˆ˜๋กœ๋ถ€ํ„ฐ ๋‹ค์Œ์˜ Eq. (4)๋ฅผ ์ด์šฉํ•˜์—ฌ cj์™€ ๐œ๋ฅผ ๊ณ„์‚ฐํ•  ์ˆ˜ ์žˆ๋‹ค.

์ˆ˜์‹  (4)

์˜ˆ์‹œ๋กœ ์•ž์„œ ๊ธฐ์ˆ ๋œ ์„ธ ์†์ƒ๋‹จ๊ณ„์— ๋Œ€ํ•œ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์„ ๋„์‹ํ™”ํ•˜์—ฌ Fig. 7์— ๋‚˜ํƒ€๋‚ด์—ˆ์œผ๋ฉฐ, Fig. 7์—์„œ E1, E2, E3 ๋ฐ E4๋Š” ๊ฐ๊ฐ ๋ฌด์†์ƒ, ๊ฒฝ๋ฏธ, ๋ณดํ†ต ๋ฐ ์‹ฌ๊ฐ ์†์ƒ์ƒํƒœ๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค.

Figure_KSCE_38_5_02_F7.jpg
Fig. 7.

Graphical Example of a Seismic Fragility Curve

4.2 ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€์‘ํ•˜๋Š” ์ˆ˜ํ‰๋ณ€์œ„๋น„

์ง€์ง„์ทจ์•ฝ๋„ ํ•จ์ˆ˜์—์„œ ์†์ƒํ•œ๊ณ„์ƒํƒœ๋Š” ๊ตฌ์กฐ๋ฌผ์˜ ์†์ƒ์ •๋„๋ฅผ ์˜ˆ์ธกํ•˜๋Š” ๊ฐ€์žฅ ํ•ฉ๋ฆฌ์ ์ธ ๋ฐฉ๋ฒ•์ด๋ฉฐ ๊ณผ๊ฑฐ ์ง€์ง„์— ๋Œ€ํ•œ ๊ตฌ์กฐ๋ฌผ์˜ ์†์ƒ๊ณผ ๊ด€๋ จํ•œ ํ†ต๊ณ„์  ๋ถ„์„ ์ž๋ฃŒ๋ผ๊ณ  ํ•  ์ˆ˜ ์žˆ๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ๋Š” ๊ธฐ์กด์˜ Dutta(1999)์™€ HAZUS(1999)๊ฐ€ ์ œ์•ˆํ•œ ๊ต๋Ÿ‰ ๊ต๊ฐ์˜ ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€์‘ํ•˜๋Š” ์ˆ˜ํ‰๋ณ€์œ„๋น„ ํ•œ๊ณ„๊ฐ’๊ณผ Jeon et al.(2014)์ด ์ œ์•ˆํ•œ ์ˆ˜ํ‰๋ณ€์œ„๋น„ ํ•œ๊ณ„๊ฐ’์„ ์ด์šฉํ•˜์—ฌ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ๋Š” ๋‹ค์„ฏ ๋‹จ๊ณ„์˜ ์†์ƒํ•œ๊ณ„์ƒํƒœ๋ฅผ ๊ณ ๋ คํ•˜์˜€๊ณ , ๊ฐ ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€์‘ํ•˜๋Š” ์ˆ˜ํ‰๋ณ€์œ„๋น„ ํ•œ๊ณ„๊ฐ’์„ ์ •๋ฆฌํ•˜์—ฌ Table 2์— ์š”์•ฝํ•˜์˜€๋‹ค.

Table 2. Lateral Drift Limits Corresponding to Damage Limit States

Damage limit state Dutta (1999) HAZUS (1999) Jeon et al. (2014)
DS1 No 0.005 - -
DS2 Slight 0.007 0.005 0.005
DS3 Moderate 0.015 0.010 0.010
DS4 Extensive 0.025 0.020 0.015
DS5 Complete 0.050 0.050 0.040

4.3 ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ 

๋Œ€์ƒ ๊ต๋Ÿ‰์— ๋Œ€ํ•œ ๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅํ•ด์„์„ ํ†ตํ•ด ๊ฐ ๊ต๊ฐ์˜ ์ตœ๋Œ€ ์ˆ˜ํ‰๋ณ€์œ„๋น„๋ฅผ ๊ตฌํ•˜์˜€๊ณ , ์ตœ๋Œ€ ์ˆ˜ํ‰๋ณ€์œ„๋น„ ๊ฒฐ๊ณผ๋ฅผ ์ด์šฉํ•˜์—ฌ ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋”ฐ๋ฅธ ์ง€์ง„๊ฐ•๋„ ๋ฒ”์œ„๋ณ„ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์„ ๊ตฌํ•˜์˜€๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ๋Š” ์ง€์ง„๊ฐ•๋„์˜ ๋ณ€์ˆ˜๋กœ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„๋ฅผ ์„ ํƒํ•˜์˜€๊ณ , ์•ž์„œ ๊ธฐ์ˆ ํ•œ ๊ฒƒ์ฒ˜๋Ÿผ ๋Œ€ํ‘œ์ ์ธ ๊ฒฝ์šฐ๋กœ Table 2์— ๋‚˜ํƒ€๋‚ธ ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€์‘ํ•˜๋Š” ๊ต๊ฐ P664์˜ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์„ Fig. 8์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค.

Figure_KSCE_38_5_02_F8.jpg
Fig. 8.

Seismic Fragility Curve of Pier P664 at Each Earthquake Intensity Range

Table 2์˜ ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€์‘ํ•˜๋Š” ์ˆ˜ํ‰๋ณ€์œ„๋น„๋กœ๋ถ€ํ„ฐ ์˜ˆ์ธกํ•  ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์ฒ˜๋Ÿผ, ๋ฌด์†์ƒ์—์„œ ์‹ฌ๊ฐ ์†์ƒ์‚ฌํƒœ ์ˆ˜์ค€์—์„œ๋Š” Dutta(1999)์˜ ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€์‘ํ•˜๋Š” ์†์ƒ์ดˆ๊ณผํ™•๋ฅ ์ด HAZUS(1999)์™€ Jeon et al.(2014)์— ์˜ํ•œ ์†์ƒ์ดˆ๊ณผํ™•๋ฅ ๋ณด๋‹ค ๋‹ค์†Œ ๋‚ฎ๊ฒŒ ์˜ˆ์ธก๋˜๋Š” ๊ฒƒ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ์ด๋Š” Dutta(1999)์— ์˜ํ•ด ์ œ์•ˆ๋œ ์ˆ˜ํ‰๋ณ€์œ„๋น„ ํ•œ๊ณ„๊ฐ’์ด ๋‹ค๋ฅธ ๋‘ ์ œ์•ˆ ํ•œ๊ณ„๊ฐ’๋ณด๋‹ค ๋‹ค์†Œ ํฌ๊ธฐ ๋•Œ๋ฌธ์ธ ๊ฒƒ์œผ๋กœ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์€ ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€ํ•œ ์˜์กด์„ฑ์ด ๋งค์šฐ ๋†’์€ ๊ฒƒ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ๋˜ํ•œ Fig. 8์—์„œ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์ฒ˜๋Ÿผ, ์ง€์ง„๊ฐ•๋„์˜ ๋ฒ”์œ„๊ฐ€ ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ์†์ƒ์ดˆ๊ณผํ™•๋ฅ ์˜ ์ฐจ์ด๊ฐ€ ์ ์  ์ปค์ ธ ๋‘ ๋ฐฐ ์ด์ƒ๊นŒ์ง€ ์ฐจ์ด๊ฐ€ ๋ฐœ์ƒํ•  ์ˆ˜ ์žˆ์–ด ๊ต๋Ÿ‰์˜ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„  ์œ ๋„ ์‹œ ์†์ƒํ•œ๊ณ„์ƒํƒœ์˜ ์„ ํƒ์ด ๋งค์šฐ ์ค‘์š”ํ•จ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ํ•œํŽธ HAZUS(1999)์™€ Jeon et al.(2014)์— ์˜ํ•ด ์ œ์•ˆ๋œ ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€์‘ํ•˜๋Š” ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์˜ ์ฐจ์ด๋Š” ๋ฏธ๋ฏธํ•˜์˜€๋‹ค.

์ง€์ง„๊ฐ•๋„๋ณ„ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„  ๋น„๊ต ๊ฒฐ๊ณผ, ์ง€์ง„๊ฐ•๋„์˜ ๋ฐฐ์œจ์กฐ์ • ๋ฒ”์œ„๋ฅผ ํฌ๊ฒŒ ํ•˜์—ฌ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜๋Š” ๊ฒฝ์šฐ ์‹ค์ œ ๊ต๋Ÿ‰์— ๋ฌผ๋ฆฌ์ ์ธ ์†์ƒ์ƒํƒœ๋ฅผ ๋ฐœ์ƒ์‹œํ‚จ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„ ๋ณด๋‹ค ๋” ํฐ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„๋ฅผ ์˜ˆ์ธกํ•˜๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ๋Œ€์ƒ ๊ต๋Ÿ‰์˜ ๊ฒฝ์šฐ ๊ณ„์ธก๋œ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„ 0.829g์—์„œ ๊ต๊ฐ์— ์‹ฌ๊ฐํ•œ ์†์ƒ์ƒํƒœ(DS4)๊ฐ€ ๋ฐœ์ƒํ•˜์˜€๊ณ , ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์„ ์‚ดํŽด๋ณด๋ฉด ์ง€์ง„๊ฐ•๋„์˜ ๋ฐฐ์œจ์กฐ์ • ๋ฒ”์œ„๋ฅผ 1.0g๋กœ ์ œํ•œํ•œ ๊ฒฝ์šฐ์— ์‹ฌ๊ฐํ•œ ์†์ƒ์ƒํƒœ์˜ ์ค‘์•™๊ฐ’์— ๋Œ€์‘ํ•˜๋Š” ์ง€์ง„๊ฐ•๋„๊ฐ€ ๊ณ„์ธก๋œ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„์— ๊ทผ์ ‘ํ•˜์—ฌ ์˜ˆ์ธกํ•จ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ํ•˜์ง€๋งŒ ์ง€์ง„๊ฐ•๋„์˜ ๋ฐฐ์œจ์กฐ์ • ๋ฒ”์œ„๋ฅผ 1.5g ๋˜๋Š” 2.0g๊นŒ์ง€ ๋†’์ธ ๊ฒฝ์šฐ์—๋Š” ์‹ฌ๊ฐํ•œ ์†์ƒ์ƒํƒœ์˜ ์ค‘์•™๊ฐ’์— ๋Œ€์‘ํ•˜๋Š” ์ง€์ง„๊ฐ•๋„๊ฐ€ ๊ณ„์ธก๋œ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„๋ณด๋‹ค ๋งค์šฐ ํฌ๊ฒŒ ์˜ˆ์ธกํ•จ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ์ด์™€ ๊ฐ™์€ ํ˜„์ƒ์€ ๊ฐ ์ง€์ง„๊ฐ•๋„ ๋ฒ”์œ„๋ณ„ ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€์‘ํ•˜๋Š” ์ค‘์•™๊ฐ’์„ ์ •๋ฆฌํ•œ Table 3์—์„œ๋„ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค. Table 3์—์„œ ์•Œ ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์ฒ˜๋Ÿผ, ์ง€์ง„๊ฐ•๋„์˜ ๋ฐฐ์œจ์กฐ์ • ๋ฒ”์œ„๋ฅผ 1.0g๋กœ ์ œํ•œํ•œ ๊ฒฝ์šฐ์˜ ์ค‘์•™๊ฐ’์ด ์‹ค์ œ ๊ณ„์ธก์ง€์ง„ํŒŒ์˜ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„์™€ ์œ ์‚ฌํ•จ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ์ด์ƒ์œผ๋กœ ์•Œ ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์ฒ˜๋Ÿผ ์ด ์—ฐ๊ตฌ์˜ ๋Œ€์ƒ ๊ต๋Ÿ‰๊ณผ ์œ ์‚ฌํ•œ ๊ต๋Ÿ‰์˜ ์†์ƒํ•œ๊ณ„์ƒํƒœ๋ณ„ ์†์ƒ์ดˆ๊ณผํ™•๋ฅ  ํ‰๊ฐ€๋ฅผ ์œ„ํ•œ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์—์„œ ์ง€์ง„๊ฐ•๋„์˜ ๋ฐฐ์œจ์กฐ์ • ๋ฒ”์œ„ ์„ค์ •์— ๋Œ€ํ•œ ๋ฉด๋ฐ€ํ•œ ๊ฒ€ํ† ๊ฐ€ ํ•„์š”ํ•  ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค.

Table 3. Median Value at Each Earthquake Intensity Range for Pier P664

Damage limit state Median value (g) at each earthquake intensity
Dutta(1999) HAZUS(1999) Jeon et al.(2014)
1.0g 1.5g 2.0g 1.0g 1.5g 2.0g 1.0g 1.5g 2.0g
DS2 0.62 0.76 0.84 0.51 0.58 0.59 0.51 0.58 0.59
DS3 0.82 1.09 1.31 0.73 0.95 1.10 0.69 0.86 0.99
DS4 0.93 1.24 1.54 0.87 1.19 1.49 0.83 1.11 1.36
DS5 - 1.40 1.74 - 1.40 1.74 - 1.38 1.71

5. ๊ฒฐ ๋ก 

์ด ์—ฐ๊ตฌ์—์„œ๋Š” ์ฒ ๊ทผ์ฝ˜ํฌ๋ฆฌํŠธ ๊ต๋Ÿ‰์— ๋Œ€ํ•œ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์—์„œ ์ง€์ง„๊ฐ•๋„์˜ ๋ฒ”์œ„๊ฐ€ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„  ์ฆ‰, ์†์ƒ์ดˆ๊ณผํ™•๋ฅ ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ๊ฒ€ํ† ํ•˜์˜€๋‹ค. ์ด๋ฅผ ์œ„ํ•ด ๊ณผ๊ฑฐ ์ง€์ง„์— ์˜ํ•ด ์‹ฌ๊ฐํ•œ ์†์ƒ์ด ๋ฐœ์ƒํ•œ ์ฒ ๊ทผ์ฝ˜ํฌ๋ฆฌํŠธ ๊ต๋Ÿ‰์„ ์„ ํƒํ•˜์—ฌ ๋น„์„ ํ˜• ๋™์  ์‹œ๊ฐ„์ด๋ ฅํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ์ด 25๊ฐœ์˜ ๊ณ„์ธก์ง€์ง„ํŒŒ๊ฐ€ ํ•ด์„์— ์‚ฌ์šฉ๋˜์—ˆ๊ณ , ๊ต๊ฐ์˜ ์ˆ˜ํ‰๋ณ€์œ„๋น„ ๋ฐ ์ตœ๋Œ€์ง€๋ฐ˜๊ฐ€์†๋„๋ฅผ ๊ฐ๊ฐ ๊ต๋Ÿ‰์˜ ์‘๋‹ต ๋ฐ ์ง€์ง„๊ฐ•๋„ ๋ณ€์ˆ˜๋กœ ์„ ํƒํ•˜์˜€๋‹ค. ์ง€์ง„๊ฐ•๋„์˜ ๋ฒ”์œ„๋ฅผ ๊ณ ๋ คํ•˜์—ฌ ์œ ๋„๋œ ๋Œ€์ƒ ๊ต๋Ÿ‰์˜ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์œผ๋กœ๋ถ€ํ„ฐ ์–ป์€ ๊ฒฐ๋ก ์„ ์ •๋ฆฌํ•˜๋ฉด ๋‹ค์Œ๊ณผ ๊ฐ™๋‹ค.

(1) ์ด ์—ฐ๊ตฌ์—์„œ ์„ ํƒํ•œ Dutta(1999), HAZUS(1999) ๊ทธ๋ฆฌ๊ณ  Jeon et al.(2014)์ด ์ œ์•ˆํ•œ ์†์ƒํ•œ๊ณ„์ƒํƒœ๋ณ„ ์ˆ˜ํ‰๋ณ€์œ„๋น„ ํ•œ๊ณ„๊ฐ’์œผ๋กœ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•œ ๊ฒฐ๊ณผ, Dutta(1999)์— ์˜ํ•œ ์†์ƒ์ดˆ๊ณผํ™•๋ฅ ์ด ๋‹ค๋ฅธ ๋‘ ๊ฒฝ์šฐ์— ๋น„ํ•ด ๋‚ฎ๊ฒŒ ์˜ˆ์ธก๋˜์—ˆ๊ณ  ์ง€์ง„๊ฐ•๋„์˜ ๋ฒ”์œ„๊ฐ€ ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ๊ทธ ์ฐจ์ด๋Š” ์ปค์ง์„ ์•Œ ์ˆ˜ ์žˆ์—ˆ๋‹ค. ์ด๋Š” ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„ ์˜ ์†์ƒ์ดˆ๊ณผํ™•๋ฅ ์ด ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ํฌ๊ฒŒ ์˜์กดํ•˜๋Š” ๊ฒƒ์œผ๋กœ ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„  ์œ ๋„ ์‹œ ์†์ƒํ•œ๊ณ„์ƒํƒœ์˜ ์„ ํƒ์ด ๋งค์šฐ ์ค‘์š”ํ•จ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค.

(2) ์ง€์ง„์ทจ์•ฝ๋„ ๊ณก์„  ๋ฐ ์ค‘์•™๊ฐ’์— ๋Œ€ํ•œ ๊ฒ€ํ†  ๊ฒฐ๊ณผ, ์ง€์ง„๊ฐ•๋„์˜ ๋ฐฐ์œจ์กฐ์ • ๋ฒ”์œ„๊ฐ€ ์ปค์งˆ์ˆ˜๋ก ์‹ค์ œ ๊ต๋Ÿ‰์— ๋ฌผ๋ฆฌ์ ์ธ ์†์ƒ์ƒํƒœ๋ฅผ ๋ฐœ์ƒ์‹œํ‚จ ์ง€์ง„๊ฐ•๋„๋ณด๋‹ค ๋” ํฐ ์ง€์ง„๊ฐ•๋„๋ฅผ ์˜ˆ์ธกํ•˜๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ๋”ฐ๋ผ์„œ ์ง€์ง„๊ฐ•๋„์˜ ๋ฐฐ์œจ์กฐ์ • ๋ฒ”์œ„๋ฅผ ์ž„์˜๋กœ ์ •ํ•˜์—ฌ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•  ๊ฒฝ์šฐ ์†์ƒ์ดˆ๊ณผํ™•๋ฅ  ์‚ฐ์ •์— ์˜ค๋ฅ˜๋ฅผ ๋ฒ”ํ•  ์ˆ˜ ์žˆ๊ณ  ์ด๋Š” ๋‚ด์ง„์„ฑ๋Šฅํ‰๊ฐ€์— ์˜ํ–ฅ์„ ๋ผ์ณ ํ•ฉ๋ฆฌ์ ์ธ ๋ณด์ˆ˜/๋ณด๊ฐ•์ด ์ด๋ฃจ์–ด์ง€์ง€ ์•Š์„ ์ˆ˜ ๋„ ์žˆ๋‹ค.

(3) ๊ฒฐ๋ก ์ ์œผ๋กœ ์ง€์ง„์ทจ์•ฝ๋„ ํ•ด์„์— ์˜ํ•œ ํ•ฉ๋ฆฌ์ ์ธ ์†์ƒ์ดˆ๊ณผํ™•๋ฅ  ์˜ˆ์ธก์„ ์œ„ํ•ด์„œ๋Š”, ๊ตญ๋‚ด ๋‚ด์ง„์„ค๊ณ„์— ๋ถ€ํ•ฉ๋˜๋Š” ์†์ƒํ•œ๊ณ„์ƒํƒœ์— ๋Œ€ํ•œ ์ •๋ฆฝ๊ณผ ํ•จ๊ป˜ ํ•ด์„์— ์ ์šฉ๋˜๋Š” ์ง€์ง„๊ฐ•๋„์˜ ๋ฒ”์œ„์— ๋Œ€ํ•œ ์—ฐ๊ตฌ๊ฐ€ ํ•„์š”ํ•  ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค.

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